Turbomachine assembly for recovering waste heat and method of using same

ABSTRACT

A turbomachine assembly for recovering waste heat generally has a compressor section that is configured to generate a compressed fluid flow and to channel the compressed fluid flow within the turbomachine assembly. A turbine section is coupled to the compressor section via a rotating member such that portions of the rotating member are located within the compressor section and the turbine section, respectively. The turbine section is in flow communication with the compressor section such that the compressed fluid flow is received by the turbine section. At least one heat exchanger is positioned at least partly within the turbine section where the heat exchanger receives waste heat energy. The heat exchanger transfers energy from the waste heat into the compressed fluid flow to increase at least one parameter of the compressed fluid flow contributing to the generation of a power output.

BACKGROUND

The field of the invention relates generally to power systems and, more particularly, to a turbomachine assembly that may be used for recovering waste heat energy from a power system for power generation.

At least some known power systems use at least one machine that is coupled to a load for the generation of a power output. The machine may be a turbomachine, such as a turbine engine, that generates mechanical torque. The load may be an electrical system, such as an electrical generator or inverter, which converts the mechanical energy to electrical energy for the power output. The load may also be coupled to an energy storage device such that some of the power output may be stored for later use. For example, at least some known power systems provide bi-directional or multi-directional electrical energy or power flow, wherein the power output from the load may be transferred to the turbine engine to power the turbine engine or the power output may be delivered to, for example, the energy storage device for storage.

At least some known power systems generate relatively large amounts of waste heat energy. For example, the turbomachines that may be used with power systems include gas turbine engines that generate waste heat energy in the form of exhaust gases. Due to environmental concerns and/or laws that companies need to adhere to, power systems may be configured to recover and reuse the waste heat energy. For example, at least some known power systems use waste heat recovery systems or assemblies that include using the turbomachines to recover and reuse the waste heat.

However, using the turbomachines themselves to recover the waste heat can be complex. For example, externally located heat exchangers may need to be installed, along with the necessary externally located piping and control valves. Such installation may take a considerable amount of time and labor. Moreover, in some circumstances, the turbomachine may need to be dismantled and reassembled for the installation of the heat exchangers and piping.

BRIEF DESCRIPTION

In an exemplary embodiment, a turbomachine assembly for recovering waste heat is provided. The turbomachine assembly generally comprises a compressor section that is configured to generate a compressed fluid flow and to channel the compressed fluid flow within the turbomachine assembly. A turbine section is coupled to the compressor section via a rotating member such that a first portion of the rotating member is positioned within the compressor section and a second portion of the rotating member is positioned within the turbine section. The turbine section is in flow communication with the compressor section such that the compressed fluid flow is received by the turbine section. At least one heat exchanger is positioned at least partly within the turbine section. The heat exchanger is configured to receive waste heat and to transmit energy from the waste heat into the compressed fluid flow to increase at least one parameter, such as pressure, temperature, or flow rate, of the compressed fluid flow contributing to the generation of a power output.

In another embodiment, a power system is provided. The power system generally comprises a load apparatus that includes a load configured to convert mechanical rotational energy to electrical energy for a power output. The power system also includes a turbomachine assembly that is coupled to the load apparatus. The turbomachine assembly includes a compressor section that is configured to generate a compressed fluid flow and to channel the compressed fluid flow within the turbomachine assembly. A turbine section is coupled to the compressor section via a rotating member such that a first end portion of the rotating member is positioned within the compressor section and a second end portion of the rotating member is positioned within the turbine section. The turbine section is in flow communication with the compressor section such that the compressed fluid flow is received by the turbine section. At least one heat exchanger is positioned at least partly within the turbine section. The heat exchanger is configured to receive waste heat and to transmit energy from the waste heat into the compressed fluid flow so as to increase at least one parameter, such as pressure, temperature, or flow rate, of the compressed fluid flow and thereby facilitate the generation of the power output.

In yet another embodiment, a method of using a turbomachine assembly for recovering waste heat is provided. The method generally comprises providing a compressor section that is configured to generate a compressed fluid flow. A turbine section is coupled to the compressor section via a rotating member such that a first end portion of the rotating member is positioned within the compressor section and a second end portion of the rotating member is positioned within the turbine section. The turbine section is in flow communication with the compressor section. At least one heat exchanger is positioned at least partly within the turbine section. The compressed fluid flow is channeled from the compressor section to the turbine section. The heat exchanger is used to receive waste heat. Energy from the waste heat is transmitted, via the heat exchanger, into the compressed fluid flow to increase at least one parameter, such as pressure, temperature, or flow rate, of the compressed fluid flow contributing to the generation of a power output.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary power system;

FIG. 2 is a perspective view of a portion of an exemplary turbomachine assembly that may be used with the power system shown in FIG. 1 and taken from area 2;

FIG. 3 is a perspective view of a portion of the turbomachine assembly shown in FIG. 2 and taken from area 3;

FIG. 4 is a side view of a portion of the turbomachine assembly shown in FIG. 2 and taken from area 4; and

FIG. 5 is a cross-sectional view of a portion of the turbomachine assembly shown in FIG. 2 and taken along line 5-5.

DETAILED DESCRIPTION

The exemplary systems and methods described herein provide a turbomachine assembly for use in a power system that may be coupled to other components/machines within the power system and the turbomachine assembly is configured to recover waste heat from within the power system, such as from the attached machine, wherein the recovered waste heat can be used for power generation. The turbomachine assembly includes a compressor section that is configured to generate a compressed fluid flow and a turbine section that is in flow communication with the compressor section and configured to receive the compressed fluid flow. At least one heat exchanger is positioned at least partly within the turbine section, wherein the heat exchanger is configured to receive waste heat and to transmit energy from the waste heat into the compressed fluid flow to increase at least one parameter of the compressed fluid flow such that the waste heat contributes to the power output. Accordingly, the turbomachine assembly is configured such that waste heat can be relatively easily recovered by the turbomachine assembly and used in the process of power generation. By using a turbomachine assembly that is configured to recover and use waste heat, a user would not need to install externally located heat exchangers, along with the necessary externally located piping and control valves in order for the power system to be able to recover and reuse waste heat therein. Moreover, any existing machines within the system may not need to be taken apart or reassembled.

FIG. 1 illustrates an exemplary power system 100. Although the exemplary embodiment illustrates a power system, the present disclosure is not limited to power systems, and one of ordinary skill in the art will appreciate that the current disclosure may be used in connection with any type of system. In the exemplary embodiment, power system 100 includes a machine 102. More specifically, in the exemplary embodiment, machine 102 is a gas turbine engine. While the exemplary embodiment includes a gas turbine engine, the present disclosure is not limited to any one particular type of machine, and one of ordinary skill in the art will appreciate that the current disclosure may be used in connection with other types of machines. For example, machine 102 may be a compressor, a pump, a turbocharger, and/or various types of turbines.

Moreover, in the exemplary embodiment, machine 102 includes an intake section 103, a compressor section 104 coupled downstream from intake section 105, a combustor section 106 coupled downstream from compressor section 104, a turbine section 107 coupled downstream from combustor section 106, and an exhaust section 108. It should be noted that, as used herein, the term “couple” is not limited to a direct or immediately sequential mechanical, thermal, flow communication, and/or an electrical connection between components, but may also include an indirect mechanical, thermal, flow communication and/or electrical connection between multiple components or through components that are placed between the coupled elements.

Turbine section 107, in the exemplary embodiment, is coupled to compressor section 104 via a drive shaft 109. In the exemplary embodiment, combustor section 106 includes a plurality of combustors 110. Combustor section 106 is coupled to compressor section 104 such that each combustor 110 is positioned in flow communication with compressor section 104. Machine 102, in the exemplary embodiment, is coupled to a turbomachine assembly 112 and to a load apparatus 114. More specifically, in the exemplary embodiment, turbine section 107 of machine 102 is coupled to load apparatus 114 via a rotor shaft 111 and exhaust section 108 of machine 102 is coupled to a turbomachine assembly 112 via a fluid conduit 113.

In the exemplary embodiment, turbomachine assembly 112 includes a compressor section (not shown in FIG. 1), a turbine section (not shown in FIG. 1) coupled downstream from the compressor section via a turbomachine assembly rotor shaft (not shown in FIG. 1), and a center section positioned between the compressor and turbine sections (not shown in FIG. 1). In one embodiment, turbomachine assembly 112 may include an energy source (not shown) and an energy injection system, such as a combustible fuel source and a fuel injection assembly, to facilitate powering turbomachine assembly 112. For example, a burner (not shown in FIG. 1) may be positioned proximate to the turbine section and/or a combustor (not shown) may be positioned in the center section. The fuel source may then channel fuel, via the fuel injection assembly, to the burner and/or to the combustor such that the energy can be used to facilitate generating combustion gases that can be used by the turbine section of turbomachine assembly 112.

Turbomachine assembly 112 is coupled to load apparatus 114 via a shaft 115. Load apparatus 114, in the exemplary embodiment, includes a load (not shown) such as an electrical system, in particular a high speed electrical generator or inverter. More specifically, in the exemplary embodiment, load apparatus 114 can comprise the load apparatus described in co-pending U.S. patent application Ser. No. 13/682,313 entitled LOAD APPARATUS AND METHOD OF USING SAME (attorney docket no. 31938-6) filed Jan. 29, 2013, which is incorporated herein by reference in its entirety. Load apparatus 114 can be coupled to an energy storage device 116, such as a battery.

Power system 100 also includes a control system 117 that is coupled to each of load apparatus 114 and turbomachine assembly 112. Control system 117, in the exemplary embodiment, is configured to control the power output produced by load apparatus 114 and to control fluid flow within turbomachine assembly 112. In the exemplary embodiment, control system 117 includes a controller 120 that is operatively coupled to vary the operation of load apparatus 114 and turbomachine assembly 112, as a function of values determined from sensors (not shown) responsive to parameters such as flow rates, rotational speed, local pressures, torque, temperatures and the like, as well as rates of change of such parameters, according to a programmed control scheme or algorithm. More specifically, controller 120 may be coupled to, for example, at least one valve (not shown) in load apparatus 114 and at least one valve (not shown in FIG. 1) in turbomachine assembly 112. Controller 120 is enabled to facilitate operative features of the valves, via features that include, without limitation, receiving permissive inputs, transmitting permissive outputs, and transmitting opening and closing commands.

In the exemplary embodiment, controller 120 may be a real-time controller and may include any suitable processor-based or microprocessor-based system, such as a computer system, that includes microcontrollers, reduced instruction set circuits (RISC), application-specific integrated circuits (ASICs), logic circuits, and/or any other circuit or processor that is capable of executing the functions described herein. In one embodiment, controller 120 may be a microprocessor that includes read-only memory (ROM) and/or random access memory (RAM), such as, for example, a 32 bit microcomputer with 2 Mbit ROM and 64 Kbit RAM. As used herein, the term “real-time” refers to outcomes occurring in a substantially short period of time after a change in the inputs affect the outcome, with the time period being a design parameter that may be selected based on the importance of the outcome and/or the capability of the system processing the inputs to generate the outcome.

Controller 120, in the exemplary embodiment, includes a memory device 130 that stores executable instructions and/or one or more operating parameters representing and/or indicating an operating condition of load apparatus 114 and of turbomachine assembly 112. Controller 120 also includes a processor 132 that is coupled to the memory device 130 via a system bus 134. In one embodiment, processor 132 may include a processing unit, such as, without limitation, an integrated circuit (IC), an application specific integrated circuit (ASIC), a microcomputer, a programmable logic controller (PLC), and/or any other programmable circuit. Alternatively, processor 132 may include multiple processing units (e.g., in a multi-core configuration). The above examples are exemplary only, and thus are not intended to limit in any way the definition and/or meaning of the term “processor.”

Moreover, in the exemplary embodiment, controller 120 includes a control interface 136 that is coupled to turbomachine assembly 112 and to load apparatus 114. More specifically, control interface 136 is coupled to the valves within turbomachine assembly 112 and within load apparatus 114, and control interface 136 is configured to control an operation of the valves. For example, processor 132 may be programmed to generate one or more control parameters that are transmitted to control interface 136. Control interface 136 may then transmit a control parameter to modulate, open, or close the valves.

Various connections are available between control interface 136 and turbomachine assembly 112 and load apparatus 114. Such connections may include, without limitation, an electrical conductor, a low-level serial data connection, such as Recommended Standard (RS) 232 or RS-485, a high-level serial data connection, such as USB, a field bus, a PROFIBUS®, or Institute of Electrical and Electronics Engineers (IEEE) 1394 (a/k/a FIREWIRE), a parallel data connection, such as IEEE 1284 or IEEE 488, a short-range wireless communication channel such as BLUETOOTH, and/or a private (e.g., inaccessible outside power system 100) network connection, whether wired or wireless. PROFIBUS is a registered trademark of Profibus Trade Organization of Scottsdale, Ariz. IEEE is a registered trademark of the Institute of Electrical and Electronics Engineers, Inc., of New York, N.Y. BLUETOOTH is a registered trademark of Bluetooth SIG, Inc. of Kirkland, Wash.

In the exemplary embodiment, control system 117 also includes at least one sensor 137 that is coupled to load apparatus 104 and to controller 120. More specifically, in the exemplary embodiment, controller 120 includes a sensor interface 140 that is coupled to sensor 137. In the exemplary embodiment, sensor 137 is positioned in close proximity to, and coupled to at least a portion of load apparatus 114. Alternatively, sensor 137 may be coupled to various other components within power system 100. In the exemplary embodiment, sensor 137 is configured to detect the level of the power output being produced by load apparatus 114. Alternatively, sensor 137 may detect various other operating parameters that enable load apparatus 114 and/or power system 100 to function as described herein.

Control system 117 also includes at least two sensors 142 and 143 that are each coupled to turbomachine assembly 112 and to controller 120. In the exemplary embodiment, sensors 142 and 143 are each positioned in close proximity to, and coupled to at least a portion of turbomachine assembly 112 and to sensor interface 140. More specifically, sensor 142 is coupled to the compressor section and sensor 143 is coupled to the turbine section of turbomachine assembly 112. In the exemplary embodiment, sensors 142 and 143 are each configured to detect various operating parameters, such as temperature and/or flow rate, within the compressor section and the turbine section, respectively.

Sensors 137, 142, and 143 each transmit a signal corresponding to their respective detected parameters to controller 120. Sensors 137, 142, and 143 may each transmit a signal continuously, periodically, or only once, for example. Other signal timings may also be contemplated. Furthermore, sensors 137, 142, and 143 may each transmit a signal either in an analog form or in a digital form. Various connections are available between sensor interface 140 and sensors 137, 142, and 143. Such connections may include, without limitation, an electrical conductor, a low-level serial data connection, such as RS 232 or RS-485, a high-level serial data connection, such as USB or IEEE® 1394, a parallel data connection, such as IEEE® 1284 or IEEE® 488, a short-range wireless communication channel such as BLUETOOTH®, and/or a private (e.g., inaccessible outside power system 100) network connection, whether wired or wireless.

Control system 117 may also include a user computing device 150 that is coupled to controller 120 via a network 149. More specifically, computing device 150 includes a communication interface 151 that is coupled to a communication interface 153 contained within controller 120. User computing device 150 includes a processor 152 for executing instructions. In some embodiments, executable instructions are stored in a memory device 154. Processor 152 may include one or more processing units (e.g., in a multi-core configuration). Memory device 154 is any device allowing information, such as executable instructions and/or other data, to be stored and retrieved.

User computing device 150 also includes at least one media output component 156 for use in presenting information to a user. Media output component 156 is any component capable of conveying information to the user. Media output component 156 may include, without limitation, a display device (not shown) (e.g., a liquid crystal display (LCD), an organic light emitting diode (OLED) display, or an audio output device (e.g., a speaker or headphones)).

Moreover, in the exemplary embodiment, user computing device 150 includes an input interface 160 for receiving input from a user. Input interface 160 may include, for example, a keyboard, a pointing device, a mouse, a stylus, a touch sensitive panel (e.g., a touch pad or a touch screen), a gyroscope, an accelerometer, a position detector, and/or an audio input device. A single component, such as a touch screen, may function as both an output device of media output component 156 and input interface 160.

During operation, intake section 103 channels air towards compressor section 104 wherein the air is compressed to a higher pressure and temperature prior to being discharged towards combustor section 106. The compressed air is mixed with fuel and other fluids and ignited to generate combustion gases that are channeled towards turbine section 107. More specifically, fuel is injected into combustors 110, and into the air flow, such as natural gas and/or fuel oil, air, diluents, and/or Nitrogen gas (N₂). The blended mixtures are ignited to generate high temperature combustion gases that are channeled towards turbine section 107. Turbine section 107 converts the thermal energy from the gas stream to mechanical rotational energy, as the combustion gases impart rotational energy to turbine section 107 and to the rotor disk assembly.

The mechanical rotational energy is converted to electrical energy via load apparatus 114 for a power output. Load apparatus 114 facilitates multi-directional power flow within power system 100 such that the power output from load apparatus 114 may be transferred to either machine 102 or to turbomachine assembly 112 to power each, or the power output may be delivered to, for example, energy storage device 116. For example, a user may initially input a predefined threshold value for a power output from load apparatus 114 via input interface 160. The predefined threshold value may be programmed with user computing device 150 and/or controller 120. As such, when the mechanical rotational energy is converted to electrical energy via load apparatus 114 for a power output, the output is detected by sensor 137. Sensor 137 then transmits a signal representative of the power output to controller 120.

Depending on whether the power output is less than, greater than, or equal to the predefined threshold, controller 120 will transmit a control parameter to the valve within load apparatus 114. For example, in the exemplary embodiment, if the power output exceeds the predefined threshold, controller 120 will transmit a control parameter to the valve such that electrical energy (i.e. power output) is channeled in a first direction 184 towards energy storage device 110 such that the power output may be stored for later use by power system 100. If the power output is below the predefined threshold, controller 120 may transmit a control parameter to the valve such that electrical energy is channeled in a second direction 186 towards machine 102 such that the power output may be used by machine 102 to generate more power or in a third direction 188 towards turbomachine assembly 112 such that the power output may be used by turbomachine assembly 112 to generate additional power.

Moreover, as explained in more detail below with respect to FIGS. 2-5, power system 100 uses turbomachine assembly 112 to recover waste heat generated within system 100 such that the waste heat contributes to power generation by the power system. For example, during operation of machine 102, waste heat, such as the exhaust gases, are generated by machine 102 and/or by the turbine section of turbomachine assembly 112. For example, the exhaust gases from machine 102 can be channeled from exhaust section 108 to turbomachine assembly 112 via conduit 113. As explained in more detail below with respect to FIGS. 2-5, the exhaust gases recovered by turbomachine assembly 112 may be used to facilitate additional power output. Control systems 117 controls the fluids being channeled within turbomachine assembly 112. The fluids being channeled within turbomachine assembly 112 enable the rotor shaft that extends from the compressor section to the turbine section to rotate, thereby facilitating the generation of mechanical rotational energy. The mechanical rotational energy is converted to electrical energy via load apparatus 114 for an additional power output. Accordingly, turbomachine assembly 112 is configured such that waste heat can be relatively easily recovered by turbomachine assembly 112 and used for power generation. By using turbomachine assembly 112, a user may simply couple turbomachine assembly 112 to machine 102. The user may not need to install externally located heat exchangers (not shown), along with the necessary externally located piping (not shown) and control valves (not shown), within power system 100 and/or take apart and reassemble machine 102 in order for power system 100 to be able to recover and reuse waste heat therein.

FIG. 2 is a perspective view of a portion of turbomachine assembly 112 taken from area 2 (shown in FIG. 1). FIG. 3 is a perspective view of a portion of turbomachine assembly 112 taken from area 3 (shown in FIG. 2). FIG. 4 is a side view of a portion of turbomachine assembly 112 taken from area 4 (shown in FIG. 2). FIG. 5 is a cross-sectional view of a portion of turbomachine assembly 112 taken along line 5-5 (shown in FIG. 2).

Referring to FIGS. 2 and 5, turbomachine assembly 112 includes a compressor section 202 and a turbine section 204 coupled to compressor section 202 via a rotor shaft 206 such that turbine section 204 is positioned downstream from compressor section 202 and such that turbine section 204 is in flow communication with compressor section 202. In the exemplary embodiment, rotor shaft 206 includes a first end portion 208, a second end portion 210, and a middle portion 211 therebetween. Rotor shaft 206 extends from compressor section 202 to turbine section 204 such that first end portion 208 of rotor shaft 206 is positioned within compressor section 202 and second end portion 210 of rotor shaft 206 is positioned within turbine section 204. A compressor rotor 212 substantially circumscribes at least a portion of first end portion 208 and a turbine rotor 214 substantially circumscribes at least a portion of second end portion 210.

In the exemplary embodiment, referring to FIGS. 4 and 5, compressor rotor 212 includes an annular base portion 201 having an exterior surface 203 and an opposing interior surface 205, wherein interior surface 205 substantially circumscribes at least a portion of first end portion 208 of rotor shaft 206 and a plurality of rotor blades 207 extend radially outwardly from base portion exterior surface 203 such that each blade 207 is substantially perpendicular with respect to exterior surface 203. Similarly, referring to FIGS. 3 and 5, turbine rotor 214 includes an annular base portion 217 having an exterior surface 209 and an opposing interior surface 213, wherein interior surface 213 substantially circumscribes at least a portion of second end portion 210 of rotor shaft 206 and a plurality of rotor blades 219 extend radially outwardly from exterior surface 209 such that each blade 219 is substantially perpendicular with respect to exterior surface 209. Turbomachine assembly 112 also includes at least two shaft bearings 216 such that one bearing 216 is adjacent to at least a portion of first end portion 208 of rotor shaft 206 and one bearing 216 is adjacent to at least a portion of second end portion 210 of rotor shaft 206.

In the exemplary embodiment, first end portion 208, middle portion 211, and second end portion 210 of rotor shaft 206 are formed integrally together such that rotor shaft 206 is a single unitary component. Alternatively, one or more of the components of rotor shaft 206 may be formed separate and removably or permanently coupled together. Each of the first end portion 208, middle portion 211, and second end portion 210 of rotor shaft 206 may be formed via a variety of manufacturing processes known in the art, such as, but not limited to, molding processes, drawing processes, or machining processes. One or more types of materials may be used to fabricate rotor shaft 206 with the materials selected based on suitability for one or more manufacturing techniques, dimensional stability, cost, moldability, workability, rigidity, and/or other characteristic of the material(s). For example, rotor shaft 206 may be at least partially formed from lightweight and rigid materials, such as an alumina material, a ceramic material, and/or a metal matrix composite material. The metal matrix composite material may include a first metal material and at least one other material, such as a second metal material and/or a ceramic compound. Alternatively, rotor shaft 206 may be formed of any suitable material that enables the turbomachine assembly 112 and/or power system 100 (shown in FIG. 1) to function as described herein.

In the exemplary embodiment, compressor section 202 is coupled to load apparatus 114 (shown in FIG. 1) such that compressor section 202 is directly adjacent to load apparatus 114. More specifically, first end portion 208 of rotor shaft 206 is coupled to drive shaft 106 (shown in FIG. 1). Referring to FIGS. 2, 4, and 5, compressor section 202 includes a cover portion 218 that is configured to substantially enclose at least a portion of first end portion 208 of rotor shaft 206 and at least a portion of compressor rotor 212 therein. Cover portion 218 may be formed via a variety of manufacturing processes known in the art, such as, but not limited to, molding processes, drawing processes, or machining processes. One or more types of materials may be used to fabricate cover portion 218 with the materials selected based on suitability for one or more manufacturing techniques, dimensional stability, cost, moldability, workability, rigidity, and/or other characteristic of the material(s). For example, cover portion 218 may be at least partially formed from a metal material.

Referring to FIG. 5, compressor section 202 includes a bypass valve 223 coupled to cover portion 218. More specifically, in the exemplary embodiment, cover portion 218 includes a channel 230 that defines a flow path 232 therein, and bypass valve 223 is positioned within flow path 232. Channel 230 is in flow communication with a compressor inlet opening 240 and a compressor bypass circuit inlet opening 242. In the exemplary embodiment, bypass valve 223 is configured to be modulated such that flow path 232 may be opened, closed, or partially opened such that fluid flow may be controlled within flow path 232. More specifically, bypass valve 223 is configured to be modulated such that fluid flow may be directed in a first direction 234 through bypass circuit inlet opening 242 and towards load apparatus 114 or in a second direction 236 through compressor inlet opening 240 and towards other components within turbomachine assembly 112.

Referring to FIGS. 2, 3, and 5, turbine section 204 includes a turbine cover portion 250 that is configured to substantially enclose at least portion of second end portion 210 of rotor shaft 206 and at least a portion of turbine rotor 214 therein. Turbine cover portion 250 may be formed via a variety of manufacturing processes known in the art, such as, but not limited to, molding processes, drawing processes, or machining processes. One or more types of materials may be used to fabricate turbine cover portion 250 with the materials selected based on suitability for one or more manufacturing techniques, dimensional stability, cost, moldability, workability, rigidity, and/or other characteristic of the material(s). For example, turbine cover portion 250 may be at least partially formed from a metal material.

In the exemplary embodiment, referring to FIG. 5, turbine cover portion 250 includes a channel 252 that defines a flow path 254 therein such that fluids, such as exhausts being emitted from turbomachine assembly 112 may be channeled through flow path 254. Moreover, cover portion 250 also includes an opening (not shown) such that channel 252 may be in flow communication with conduit 113 (shown in FIG. 1) to facilitate the channeling of exhausts from machine 102 to be channeled to turbine section 204 of turbomachine assembly 112. A burner 258 may be included within turbine section 204. Nozzle ring 256, in the exemplary embodiment, may be a stationary nozzle ring that is configured to facilitate the optimization of work energy utilization for turbine rotor 214.

Moreover, in the exemplary embodiment, at least one heat exchanger 259 is positioned within turbine section 204, wherein heat exchanger 259 is configured to receive waste heat, such as exhaust gases, from machine 102 and/or from turbomachine assembly 112. For example, heat exchanger 259 may be positioned adjacent to the cover portion opening such that exhaust gases being channeled to turbine section 204 from exhaust section 108 of machine 102 may be recovered by heat exchanger 259. Exhaust gases being generated by turbine section 204 may also be recovered by heat exchanger 259. In the exemplary embodiment, heat exchanger 259 may be any suitable type of heat exchanger known in the art, such as a compact heat exchanger that is configured to be received and positioned within turbine section 204.

Referring to FIGS. 3 and 5, turbine section 204, in the exemplary embodiment, also includes an annular nozzle ring 290 that is positioned adjacent to bearing 216. Nozzle ring 290, in the exemplary embodiment, may be a stationary nozzle ring that is configured to facilitate the optimization of work energy utilization for turbine rotor 214. Nozzle ring 290 includes a surface 291 and a plurality of nozzle vanes 292 that extend outwardly from surface 291. In the exemplary embodiment, nozzle ring 290, along with surface 291 and vanes 292, are integrally formed together. Alternatively, nozzle ring 290, along with surface 291 and vanes 292, may be formed as separate parts that are removably or permanently coupled together.

Nozzle ring 290, along with surface 292 and vanes 292, may be formed via a variety of manufacturing processes known in the art, such as, but not limited to, molding processes, drawing processes, or machining processes. One or more types of materials may be used to fabricate nozzle ring 290, along with surface 292 and vanes 292, with the materials selected based on suitability for one or more manufacturing techniques, dimensional stability, cost, moldability, workability, rigidity, and/or other characteristic of the material(s). For example, nozzle ring 290, along with surface 292 and vanes 292, may be at least partially formed from a metal material. Nozzle ring 290, along with surface 291 and vanes 292, can be a part of or an extension of turbine cover portion 250, in which case, nozzle ring 290 may be fabricated of the same material as turbine cover portion 250. Alternatively, nozzle ring 290, along with surface 291 and vanes 292, can be a separate component from turbine cover portion 250. Moreover, turbine section 204 may also include a heat isolating shield 300 that substantially circumscribes at least a portion of second end portion 210 of rotor shaft 206. In the exemplary embodiment, heat isolating shield 300 is positioned between nozzle ring 290 and turbine rotor 214. Heat isolating shield 300 may be fabricated from any suitable material, such as a sheet metal.

Turbomachine assembly 112 also includes a center section 260 positioned between compressor section 202 and turbine section 204. A housing assembly 262 substantially encloses at least a portion of center section 260 and is also positioned between compressor section 202 and turbine section 204. Housing assembly 262, in the exemplary embodiment, substantially circumscribes at least a portion of middle portion 211 of rotor shaft 206 and encloses components of center section 260 therein. For example, as discussed above, a combustor section (not shown) and/or energy sources (not shown) may be positioned within center section 260 and enclosed by housing assembly 262.

Housing assembly 262 may be formed via a variety of manufacturing processes known in the art, such as, but not limited to, molding processes, drawing processes, or machining processes. One or more types of materials may be used to fabricate housing assembly 262 with the materials selected based on suitability for one or more manufacturing techniques, dimensional stability, cost, moldability, workability, rigidity, and/or other characteristic of the material(s). For example, housing assembly 262 may be at least partially formed from a metal material.

In the exemplary embodiment, housing assembly 262 includes two conduits 270 extending from compressor section 202 to turbine section 204 such that fluid can flow through each of the conduits 270 and be channeled between compressor section 202 and turbine section 204. Housing assembly 262 also includes at least one regulating valve 272 that is/are each in flow communication with compressor section 202 and turbine section 204. More specifically, in the exemplary embodiment, housing assembly 262 includes two regulating valves 272 such that each regulating valve 272 is positioned within a separate conduit 270. Each regulating valve 272 is configured to be modulated such the respective conduit 270 may be opened, closed, or partially opened such that fluid flow may be controlled within each conduit. More specifically, each regulating valve 272 is configured to be modulated such that fluid flow may be directed in a first direction 280 towards compressor section 202 or in a second direction 282 towards turbine section 204.

While two regulating valves 272 are included within the exemplary embodiment, housing assembly 262 may have any number of regulating valves 272 that enables turbomachine assembly 112 and/or power system 100 to function as described herein. Moreover, the location of regulating valves 272 are not limited to center section 260. For example, regulating valve 272 may be positioned within compressor section 202. More specifically, in some embodiments turbomachine assembly 112 may not have center section 260 included therein. As such, turbomachine assembly 112 would include compressor section 202 and turbine section 204 positioned adjacent to compressor section 202, and at least one regulating valve 272 would be positioned within compressor section 202.

Moreover, as discussed above, turbomachine assembly 112 also includes two shaft bearings 216 such that one bearing 216 is adjacent to at least a portion of first end portion 208 of rotor shaft 206 and one bearing 216 is adjacent to at least a portion of second end portion 210 of rotor shaft 206. More specifically, each bearing 216 is positioned within center section 260 such that one bearing 216 is adjacent to at least a portion of first end portion 208 of rotor shaft 206 and one bearing 216 is adjacent to at least a portion of second end portion 210 of rotor shaft 206. While bearings 216 are positioned within center section 260, bearings are not limited to being positioned within center section 260. For example, as discussed above, in some embodiments turbomachine assembly 112 may not have center section 260 included therein. As such, turbomachine assembly 112 would include compressor section 202 and turbine section 204 positioned adjacent to compressor section 202, and one bearing 216 would be positioned within compressor section 202 and another bearing 216 would be positioned within turbine section 204.

During operation of power system 100, machine 102 and at least some portions of turbomachine assembly 112 generate waste heat. More specifically, the combustion gases generated and used by machine 102 to power machine 102 may cause the emission of exhaust gases. More specifically, when fuel such as natural gas and/or fuel oil, air, diluents, and/or Nitrogen gas (N₂), is injected into combustors 110 (shown in FIG. 1) of machine 102, and into the compressed air flow, the blended mixtures are ignited to generate high temperature combustion gases that are channeled towards turbine section 107 (shown in FIG. 1) of machine 102. While turbine section 107 converts a portion of the thermal energy from the gas stream to mechanical rotational energy, some of the thermal energy is emitted as exhaust gases via exhaust section 108 (shown in FIG. 1) of machine 102.

Similarly, the use of burner 258 within turbine section 204 of turbomachine assembly 112 may cause the generation of exhaust gases from turbine section 204. For example, with regard to turbomachine assembly 112, air is channeled to compressor section 202 via inlet opening 240, wherein the air is compressed to a higher pressure and temperature. The air flows through channel 230 within flow path 232. At this time, bypass valve 223 is not obstructing flow path 232 such that the air can be channeled in second direction 236 towards center section 260. The compressed air may then be mixed with fuel and other fluids and ignited to generate combustion gases that are channeled towards turbine section 204. A combustor (not shown) within center section 260 or burner 258 may ignite the fuel mixture to generate expanding high temperature combustion gases that are channeled towards turbine section 204 such that turbine section 204 can convert the thermal energy from the combustion gas stream to mechanical rotational energy. This process within turbomachine assembly 112 may cause the emission of exhaust gases.

The exhaust gases emitted by machine 102 can be channeled from exhaust section 108, via conduit 113, to turbine section 204 of turbomachine assembly 112. Heat exchanger 259 can receive and recover the exhaust gases received from exhaust section 108 and/or the exhaust gases generated within turbine section 204. As additional compressed air is channeled from compressor section 202 to turbine section 204, energy from the waste heat recovered by heat exchanger 259 can be transmitted by heat exchanger 259 into the compressed air. When the waste heat is applied to the compressed air, the compressed air is energized. More specifically, at least one parameter of the compressed air is substantially increased. For example, the pressure, temperature, the velocity, and/or another aspect of the enthalpy of the compressed air is increased. Burner 258 may provide additional heat to the compressed air combined within the recovered waste heat to further energize the compressed air, such as increasing the temperature of the air.

The compressed air combined with the waste heat is channeled to nozzle ring 290, which channels the compressed air combined with the waste heat over turbine rotor 214. As fluid flow is channeled to turbine section 204, nozzle ring 290 channels the fluid flow over turbine rotor 214. In the exemplary embodiment, the shape and configuration of nozzle ring 290 can change the direction of the fluid flow as well accelerate the fluid flow. For example, vanes 292 may direct the fluid flow and facilitate accelerating the fluid flow that is channeled to turbine section 204. Vanes 292 direct the fluid flow to be channeled over blades 219 to facilitate rotating rotor 214 and shaft 206 such that mechanical rotational energy can be generated. The mechanical rotational energy is converted to electrical energy via load apparatus 114 for a power output. This additional power output may be transferred to either machine 102 or to turbomachine assembly 112 to provide additional power to each, or the power output may be delivered to, for example, energy storage device 116 (shown in FIG. 1).

Moreover, the fluid flow within turbomachine assembly 112 may be controlled via control system 117 (shown in FIG. 1). For example, controller 120 (shown in FIG. 1) can modulate each of bypass valve 223 and regulating valve 272 to control the flow of the compressed air within turbomachine assembly 114. There may be additional components included within turbomachine assembly 112 and/or turbomachine assembly 112 may have various other functions. For example, turbomachine assembly 112 can comprise the turbomachine assembly and components therein described in co-pending U.S. patent application Ser. No. ______ entitled TURBOMACHINE ASSEMBLY AND METHOD OF USING SAME (attorney docket no. F9941-00008) filed May, 2013, which is incorporated herein by reference in its entirety.

As compared to known power systems that are configured to recover waste heat from within the system, the embodiments described herein provide a turbomachine assembly that facilitates an efficient solution to recovering waste heat that does not require a considerable amount of time and labor for installation and any existing machines within the system may not need to be taken apart or reassembled. More specifically, the embodiments described herein provide a turbomachine assembly for use in a power system that may be coupled to other components/machines within the power system and the turbomachine assembly is configured to recover waste heat from within the power system, such as from the attached machine, wherein the recovered waste heat can be used for power generation. The turbomachine assembly includes a compressor section that is configured to generate a compressed fluid flow and a turbine section that is in flow communication with the compressor section and configured to receive the compressed fluid flow. At least one heat exchanger is positioned within the turbine section, wherein the heat exchanger is configured to receive waste heat and to transmit the waste heat into the compressed fluid flow to increase at least one parameter of the compressed fluid flow such that a power output is generated by the waste heat. Accordingly, the turbomachine assembly is configured such that waste heat can be relatively easily recovered by the turbomachine assembly and used for power generation. By using a turbomachine assembly that is configured to recover and use waste heat, a user would not need to install externally located heat exchangers, along with the necessary externally located piping and control valves in order for the power system to be able to recover and reuse waste heat therein. Moreover, any existing machines within the system may not need to be taken apart or reassembled.

Exemplary embodiments of systems, apparatus, and methods are described above in detail. The systems, apparatus, and methods are not limited to the specific embodiments described herein, but rather, components of each system, apparatus, and/or method may be utilized independently and separately from other components described herein. For example, each system may also be used in combination with other systems and is not limited to practice with only systems as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other applications.

Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 

What is claimed is:
 1. A turbomachine assembly for recovering waste heat, said turbomachine assembly comprising: a compressor section configured to generate a compressed fluid flow and to channel the compressed fluid flow within said turbomachine assembly; a turbine section coupled to said compressor section via a rotating member such that a first portion of the rotating member is positioned within said compressor section and a second portion of the rotating member is positioned within said turbine section, wherein said turbine section is in flow communication with said compressor section such that the compressed fluid flow is received by said turbine section; and at least one heat exchanger positioned at least partly within said turbine section, wherein said at least one heat exchanger is configured to receive waste heat and to transfer energy from the waste heat into the compressed fluid flow so as to increase at least one parameter of the compressed fluid flow contributing to the generation of a power output.
 2. A turbomachine assembly in accordance with claim 1, wherein said at least one heat exchanger is configured to receive the waste heat from said turbine section.
 3. A turbomachine assembly in accordance with claim 1, wherein said at least one heat exchanger is configured to receive the waste heat from a machine that is coupled to said turbine section.
 4. A turbomachine assembly in accordance with claim 1, further comprising at least one burner positioned within said turbine section, wherein said at least one burner is configured to provide additional heat to the compressed fluid flow combined with the waste heat.
 5. A turbomachine assembly in accordance with claim 1, wherein said turbine section further comprises a rotor comprising an annular base portion that is configured to substantially circumscribe at least a portion of the second end portion of the rotating member, said rotor further comprises a plurality blades extending radially outwardly from a surface of said base portion.
 6. A turbomachine assembly in accordance with claim 5, further comprising at least one nozzle ring positioned within said turbine section, wherein said at least one nozzle ring is configured to channel the compressed fluid flow combined with the waste heat over said rotor to facilitate rotating the rotating member.
 7. A turbomachine assembly in accordance with claim 1, further comprising a center section positioned between said compressor section and said turbine section, wherein said center section includes at least one conduit that is configured to channel the compressed fluid flow from said compressor section to said turbine section.
 8. A power system comprising: a load apparatus comprising a load configured to convert mechanical rotational energy to electrical energy for a power output; and a turbomachine assembly coupled to said load apparatus, said turbomachine assembly comprises: a compressor section configured to generate a compressed fluid flow and to channel the compressed fluid flow within said turbomachine assembly; a turbine section coupled to said compressor section via a rotating member such that a first portion of the rotating member is positioned within said compressor section and a second portion of the rotating member is positioned within said turbine section, wherein said turbine section is in flow communication with said compressor section such that the compressed fluid flow is received by said turbine section; and at least one heat exchanger positioned at least partly within said turbine section, wherein said at least one heat exchanger is configured to receive waste heat and to transfer energy from the waste heat into the compressed fluid flow so as to increase at least one parameter of the compressed fluid flow contributing to the generation of the power output.
 9. A power system in accordance with claim 8, wherein said at least one heat exchanger is configured to receive the waste heat from said turbine section.
 10. A power system in accordance with claim 8, further comprising at least one machine coupled to said turbomachine assembly, wherein said at least one heat exchanger is configured to receive the waste heat from said at least one machine.
 11. A power system in accordance with claim 10, wherein said at least one machine comprises at least one gas turbine engine, said at least one heat exchanger is configured to receive the waste heat from exhaust gases generated by said at least one gas turbine engine.
 12. A power system in accordance with claim 8, wherein said turbomachine assembly further comprises at least one burner positioned within said turbine section, wherein said at least one burner is configured to provide additional heat to the compressed fluid flow combined with the waste heat.
 13. A power system in accordance with claim 8, wherein said turbine section further comprises a rotor comprising an annular base portion that is configured to substantially circumscribe at least a portion of the second end portion of the rotating member, said rotor further comprises a plurality blades extending radially outwardly from a surface of said base portion.
 14. A power system in accordance with claim 13, wherein said turbomachine assembly further comprises at least one nozzle ring positioned within said turbine section, wherein said at least one nozzle ring is configured to channel the compressed fluid flow combined with the waste heat over said rotor to facilitate rotating the rotating member.
 15. A power system in accordance with claim 8, wherein said turbomachine assembly further comprises a center section positioned between said compressor section and said turbine section, wherein said center section includes at least one conduit that is configured to channel the compressed fluid flow from said compressor section to said turbine section.
 16. A method of using a turbomachine assembly for recovering waste heat, said method comprising: providing a compressor section that is configured to generate a compressed fluid flow; coupling a turbine section to the compressor section via a rotating member such that a first portion of the rotating member is positioned within the compressor section and a second portion of the rotating member is positioned within the turbine section, wherein the turbine section is in flow communication with the compressor section; positioning at least one heat exchanger at least partly within the turbine section; channeling the compressed fluid flow from the compressor section to the turbine section; using the at least one heat exchanger to receive waste heat; and transferring energy from the waste heat, via the at least one heat exchanger, into the compressed fluid flow to increase at least one parameter of the compressed fluid flow contributing to generation of a power output.
 17. A method in accordance with claim 16, wherein using the at least one heat exchanger to receive waste heat further comprises using the at least one heat exchanger to receive waste heat from the turbine section.
 18. A method in accordance with claim 16, wherein using the at least one heat exchanger to receive waste heat further comprises using the at least one heat exchanger to receive waste heat from a machine that is coupled to the turbine section.
 19. A method in accordance with claim 16, further comprising providing additional heat to the compressed fluid flow combined with the waste heat via at least one burner that is positioned within the turbine section.
 20. A method in accordance with claim 16, further comprising channeling the compressed fluid flow combined with the waste heat over at least one component within the turbine section via at least one nozzle ring positioned within the turbine section. 